Thoracic Spinal Cord Injuries The thoracic spine is located in the upper and middle part of the back. Twelve vertebrae are located in the thoracic spine, and are numbered T-1 to T-12. Each number corresponds with the nerves in that section of the spinal cord: T-1 through T-5 nerves affect muscles, upper chest, mid-back and abdominal muscles. These nerves and muscles help control the rib cage, lungs, diaphragm and muscles that help you breathe. T-6 through T-12 nerves affect abdominal and back muscles. These nerves and muscles are important for balance and posture, and they help you cough or expel foreign matter from your airway. The thoracic spine is built for stability and helps keep the body upright. It connects the cervical spine, which is located in the neck, and the lumbar spine, which is located in the lower back. General Effects of Injury to Thoracic Nerves – T-1 to T-5 Injuries usually affect the abdominal and lower back muscles and the legs, typically resu